// Copyright 2007, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Google Mock - a framework for writing C++ mock classes.
//
// This file implements the ON_CALL() and EXPECT_CALL() macros.
//
// A user can use the ON_CALL() macro to specify the default action of
// a mock method.  The syntax is:
//
//   ON_CALL(mock_object, Method(argument-matchers))
//       .With(multi-argument-matcher)
//       .WillByDefault(action);
//
//  where the .With() clause is optional.
//
// A user can use the EXPECT_CALL() macro to specify an expectation on
// a mock method.  The syntax is:
//
//   EXPECT_CALL(mock_object, Method(argument-matchers))
//       .With(multi-argument-matchers)
//       .Times(cardinality)
//       .InSequence(sequences)
//       .After(expectations)
//       .WillOnce(action)
//       .WillRepeatedly(action)
//       .RetiresOnSaturation();
//
// where all clauses are optional, and .InSequence()/.After()/
// .WillOnce() can appear any number of times.

// GOOGLETEST_CM0002 DO NOT DELETE

#ifndef GMOCK_INCLUDE_GMOCK_GMOCK_SPEC_BUILDERS_H_
#define GMOCK_INCLUDE_GMOCK_GMOCK_SPEC_BUILDERS_H_

#include <map>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include "gmock/gmock-actions.h"
#include "gmock/gmock-cardinalities.h"
#include "gmock/gmock-matchers.h"
#include "gmock/internal/gmock-internal-utils.h"
#include "gmock/internal/gmock-port.h"
#include "gtest/gtest.h"

#if GTEST_HAS_EXCEPTIONS
#include <stdexcept> // NOLINT
#endif

GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 /* class A needs to have dll-interface to be used by clients of class B */)

namespace testing {

// An abstract handle of an expectation.
class Expectation;

// A set of expectation handles.
class ExpectationSet;

// Anything inside the 'internal' namespace IS INTERNAL IMPLEMENTATION
// and MUST NOT BE USED IN USER CODE!!!
namespace internal {

// Implements a mock function.
template<typename F>
class FunctionMocker;

// Base class for expectations.
class ExpectationBase;

// Implements an expectation.
template<typename F>
class TypedExpectation;

// Helper class for testing the Expectation class template.
class ExpectationTester;

// Base class for function mockers.
template<typename F>
class FunctionMockerBase;

// Protects the mock object registry (in class Mock), all function
// mockers, and all expectations.
//
// The reason we don't use more fine-grained protection is: when a
// mock function Foo() is called, it needs to consult its expectations
// to see which one should be picked.  If another thread is allowed to
// call a mock function (either Foo() or a different one) at the same
// time, it could affect the "retired" attributes of Foo()'s
// expectations when InSequence() is used, and thus affect which
// expectation gets picked.  Therefore, we sequence all mock function
// calls to ensure the integrity of the mock objects' states.
GTEST_API_ GTEST_DECLARE_STATIC_MUTEX_(g_gmock_mutex);

// Untyped base class for ActionResultHolder<R>.
class UntypedActionResultHolderBase;

// Abstract base class of FunctionMockerBase.  This is the
// type-agnostic part of the function mocker interface.  Its pure
// virtual methods are implemented by FunctionMockerBase.
class GTEST_API_ UntypedFunctionMockerBase
{
public:
    UntypedFunctionMockerBase();
    virtual ~UntypedFunctionMockerBase();

    // Verifies that all expectations on this mock function have been
    // satisfied.  Reports one or more Google Test non-fatal failures
    // and returns false if not.
    bool VerifyAndClearExpectationsLocked()
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);

    // Clears the ON_CALL()s set on this mock function.
    virtual void ClearDefaultActionsLocked()
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) = 0;

    // In all of the following Untyped* functions, it's the caller's
    // responsibility to guarantee the correctness of the arguments'
    // types.

    // Performs the default action with the given arguments and returns
    // the action's result.  The call description string will be used in
    // the error message to describe the call in the case the default
    // action fails.
    // L = *
    virtual UntypedActionResultHolderBase *UntypedPerformDefaultAction(
        void *untyped_args, const std::string &call_description) const = 0;

    // Performs the given action with the given arguments and returns
    // the action's result.
    // L = *
    virtual UntypedActionResultHolderBase *UntypedPerformAction(
        const void *untyped_action, void *untyped_args) const = 0;

    // Writes a message that the call is uninteresting (i.e. neither
    // explicitly expected nor explicitly unexpected) to the given
    // ostream.
    virtual void UntypedDescribeUninterestingCall(
        const void *untyped_args,
        ::std::ostream *os) const
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex) = 0;

    // Returns the expectation that matches the given function arguments
    // (or NULL is there's no match); when a match is found,
    // untyped_action is set to point to the action that should be
    // performed (or NULL if the action is "do default"), and
    // is_excessive is modified to indicate whether the call exceeds the
    // expected number.
    virtual const ExpectationBase *UntypedFindMatchingExpectation(
        const void *untyped_args,
        const void **untyped_action, bool *is_excessive,
        ::std::ostream *what, ::std::ostream *why)
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex) = 0;

    // Prints the given function arguments to the ostream.
    virtual void UntypedPrintArgs(const void *untyped_args,
                                  ::std::ostream *os) const = 0;

    // Sets the mock object this mock method belongs to, and registers
    // this information in the global mock registry.  Will be called
    // whenever an EXPECT_CALL() or ON_CALL() is executed on this mock
    // method.
    // FIXME: rename to SetAndRegisterOwner().
    void RegisterOwner(const void *mock_obj)
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex);

    // Sets the mock object this mock method belongs to, and sets the
    // name of the mock function.  Will be called upon each invocation
    // of this mock function.
    void SetOwnerAndName(const void *mock_obj, const char *name)
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex);

    // Returns the mock object this mock method belongs to.  Must be
    // called after RegisterOwner() or SetOwnerAndName() has been
    // called.
    const void *MockObject() const
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex);

    // Returns the name of this mock method.  Must be called after
    // SetOwnerAndName() has been called.
    const char *Name() const
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex);

    // Returns the result of invoking this mock function with the given
    // arguments.  This function can be safely called from multiple
    // threads concurrently.  The caller is responsible for deleting the
    // result.
    UntypedActionResultHolderBase *UntypedInvokeWith(void *untyped_args)
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex);

protected:
    typedef std::vector<const void *> UntypedOnCallSpecs;

    typedef std::vector<internal::linked_ptr<ExpectationBase>>
        UntypedExpectations;

    // Returns an Expectation object that references and co-owns exp,
    // which must be an expectation on this mock function.
    Expectation GetHandleOf(ExpectationBase *exp);

    // Address of the mock object this mock method belongs to.  Only
    // valid after this mock method has been called or
    // ON_CALL/EXPECT_CALL has been invoked on it.
    const void *mock_obj_; // Protected by g_gmock_mutex.

    // Name of the function being mocked.  Only valid after this mock
    // method has been called.
    const char *name_; // Protected by g_gmock_mutex.

    // All default action specs for this function mocker.
    UntypedOnCallSpecs untyped_on_call_specs_;

    // All expectations for this function mocker.
    //
    // It's undefined behavior to interleave expectations (EXPECT_CALLs
    // or ON_CALLs) and mock function calls.  Also, the order of
    // expectations is important.  Therefore it's a logic race condition
    // to read/write untyped_expectations_ concurrently.  In order for
    // tools like tsan to catch concurrent read/write accesses to
    // untyped_expectations, we deliberately leave accesses to it
    // unprotected.
    UntypedExpectations untyped_expectations_;
}; // class UntypedFunctionMockerBase

// Untyped base class for OnCallSpec<F>.
class UntypedOnCallSpecBase
{
public:
    // The arguments are the location of the ON_CALL() statement.
    UntypedOnCallSpecBase(const char *a_file, int a_line)
        : file_(a_file)
        , line_(a_line)
        , last_clause_(kNone)
    {
    }

    // Where in the source file was the default action spec defined?
    const char *file() const { return file_; }
    int line() const { return line_; }

protected:
    // Gives each clause in the ON_CALL() statement a name.
    enum Clause {
        // Do not change the order of the enum members!  The run-time
        // syntax checking relies on it.
        kNone,
        kWith,
        kWillByDefault
    };

    // Asserts that the ON_CALL() statement has a certain property.
    void AssertSpecProperty(bool property,
                            const std::string &failure_message) const
    {
        Assert(property, file_, line_, failure_message);
    }

    // Expects that the ON_CALL() statement has a certain property.
    void ExpectSpecProperty(bool property,
                            const std::string &failure_message) const
    {
        Expect(property, file_, line_, failure_message);
    }

    const char *file_;
    int line_;

    // The last clause in the ON_CALL() statement as seen so far.
    // Initially kNone and changes as the statement is parsed.
    Clause last_clause_;
}; // class UntypedOnCallSpecBase

// This template class implements an ON_CALL spec.
template<typename F>
class OnCallSpec : public UntypedOnCallSpecBase
{
public:
    typedef typename Function<F>::ArgumentTuple ArgumentTuple;
    typedef typename Function<F>::ArgumentMatcherTuple ArgumentMatcherTuple;

    // Constructs an OnCallSpec object from the information inside
    // the parenthesis of an ON_CALL() statement.
    OnCallSpec(const char *a_file, int a_line,
               const ArgumentMatcherTuple &matchers)
        : UntypedOnCallSpecBase(a_file, a_line)
        , matchers_(matchers)
        ,
        // By default, extra_matcher_ should match anything.  However,
        // we cannot initialize it with _ as that triggers a compiler
        // bug in Symbian's C++ compiler (cannot decide between two
        // overloaded constructors of Matcher<const ArgumentTuple&>).
        extra_matcher_(A<const ArgumentTuple &>())
    {
    }

    // Implements the .With() clause.
    OnCallSpec &With(const Matcher<const ArgumentTuple &> &m)
    {
        // Makes sure this is called at most once.
        ExpectSpecProperty(last_clause_ < kWith,
                           ".With() cannot appear "
                           "more than once in an ON_CALL().");
        last_clause_ = kWith;

        extra_matcher_ = m;
        return *this;
    }

    // Implements the .WillByDefault() clause.
    OnCallSpec &WillByDefault(const Action<F> &action)
    {
        ExpectSpecProperty(last_clause_ < kWillByDefault,
                           ".WillByDefault() must appear "
                           "exactly once in an ON_CALL().");
        last_clause_ = kWillByDefault;

        ExpectSpecProperty(!action.IsDoDefault(),
                           "DoDefault() cannot be used in ON_CALL().");
        action_ = action;
        return *this;
    }

    // Returns true iff the given arguments match the matchers.
    bool Matches(const ArgumentTuple &args) const
    {
        return TupleMatches(matchers_, args) && extra_matcher_.Matches(args);
    }

    // Returns the action specified by the user.
    const Action<F> &GetAction() const
    {
        AssertSpecProperty(last_clause_ == kWillByDefault,
                           ".WillByDefault() must appear exactly "
                           "once in an ON_CALL().");
        return action_;
    }

private:
    // The information in statement
    //
    //   ON_CALL(mock_object, Method(matchers))
    //       .With(multi-argument-matcher)
    //       .WillByDefault(action);
    //
    // is recorded in the data members like this:
    //
    //   source file that contains the statement => file_
    //   line number of the statement            => line_
    //   matchers                                => matchers_
    //   multi-argument-matcher                  => extra_matcher_
    //   action                                  => action_
    ArgumentMatcherTuple matchers_;
    Matcher<const ArgumentTuple &> extra_matcher_;
    Action<F> action_;
}; // class OnCallSpec

// Possible reactions on uninteresting calls.
enum CallReaction {
    kAllow,
    kWarn,
    kFail,
};

} // namespace internal

// Utilities for manipulating mock objects.
class GTEST_API_ Mock
{
public:
    // The following public methods can be called concurrently.

    // Tells Google Mock to ignore mock_obj when checking for leaked
    // mock objects.
    static void AllowLeak(const void *mock_obj)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

    // Verifies and clears all expectations on the given mock object.
    // If the expectations aren't satisfied, generates one or more
    // Google Test non-fatal failures and returns false.
    static bool VerifyAndClearExpectations(void *mock_obj)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

    // Verifies all expectations on the given mock object and clears its
    // default actions and expectations.  Returns true iff the
    // verification was successful.
    static bool VerifyAndClear(void *mock_obj)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

private:
    friend class internal::UntypedFunctionMockerBase;

    // Needed for a function mocker to register itself (so that we know
    // how to clear a mock object).
    template<typename F>
    friend class internal::FunctionMockerBase;

    template<typename M>
    friend class NiceMock;

    template<typename M>
    friend class NaggyMock;

    template<typename M>
    friend class StrictMock;

    // Tells Google Mock to allow uninteresting calls on the given mock
    // object.
    static void AllowUninterestingCalls(const void *mock_obj)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

    // Tells Google Mock to warn the user about uninteresting calls on
    // the given mock object.
    static void WarnUninterestingCalls(const void *mock_obj)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

    // Tells Google Mock to fail uninteresting calls on the given mock
    // object.
    static void FailUninterestingCalls(const void *mock_obj)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

    // Tells Google Mock the given mock object is being destroyed and
    // its entry in the call-reaction table should be removed.
    static void UnregisterCallReaction(const void *mock_obj)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

    // Returns the reaction Google Mock will have on uninteresting calls
    // made on the given mock object.
    static internal::CallReaction GetReactionOnUninterestingCalls(
        const void *mock_obj)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

    // Verifies that all expectations on the given mock object have been
    // satisfied.  Reports one or more Google Test non-fatal failures
    // and returns false if not.
    static bool VerifyAndClearExpectationsLocked(void *mock_obj)
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(internal::g_gmock_mutex);

    // Clears all ON_CALL()s set on the given mock object.
    static void ClearDefaultActionsLocked(void *mock_obj)
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(internal::g_gmock_mutex);

    // Registers a mock object and a mock method it owns.
    static void Register(
        const void *mock_obj,
        internal::UntypedFunctionMockerBase *mocker)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

    // Tells Google Mock where in the source code mock_obj is used in an
    // ON_CALL or EXPECT_CALL.  In case mock_obj is leaked, this
    // information helps the user identify which object it is.
    static void RegisterUseByOnCallOrExpectCall(
        const void *mock_obj, const char *file, int line)
        GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);

    // Unregisters a mock method; removes the owning mock object from
    // the registry when the last mock method associated with it has
    // been unregistered.  This is called only in the destructor of
    // FunctionMockerBase.
    static void UnregisterLocked(internal::UntypedFunctionMockerBase *mocker)
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(internal::g_gmock_mutex);
}; // class Mock

// An abstract handle of an expectation.  Useful in the .After()
// clause of EXPECT_CALL() for setting the (partial) order of
// expectations.  The syntax:
//
//   Expectation e1 = EXPECT_CALL(...)...;
//   EXPECT_CALL(...).After(e1)...;
//
// sets two expectations where the latter can only be matched after
// the former has been satisfied.
//
// Notes:
//   - This class is copyable and has value semantics.
//   - Constness is shallow: a const Expectation object itself cannot
//     be modified, but the mutable methods of the ExpectationBase
//     object it references can be called via expectation_base().
//   - The constructors and destructor are defined out-of-line because
//     the Symbian WINSCW compiler wants to otherwise instantiate them
//     when it sees this class definition, at which point it doesn't have
//     ExpectationBase available yet, leading to incorrect destruction
//     in the linked_ptr (or compilation errors if using a checking
//     linked_ptr).
class GTEST_API_ Expectation
{
public:
    // Constructs a null object that doesn't reference any expectation.
    Expectation();

    ~Expectation();

    // This single-argument ctor must not be explicit, in order to support the
    //   Expectation e = EXPECT_CALL(...);
    // syntax.
    //
    // A TypedExpectation object stores its pre-requisites as
    // Expectation objects, and needs to call the non-const Retire()
    // method on the ExpectationBase objects they reference.  Therefore
    // Expectation must receive a *non-const* reference to the
    // ExpectationBase object.
    Expectation(internal::ExpectationBase &exp); // NOLINT

    // The compiler-generated copy ctor and operator= work exactly as
    // intended, so we don't need to define our own.

    // Returns true iff rhs references the same expectation as this object does.
    bool operator==(const Expectation &rhs) const
    {
        return expectation_base_ == rhs.expectation_base_;
    }

    bool operator!=(const Expectation &rhs) const { return !(*this == rhs); }

private:
    friend class ExpectationSet;
    friend class Sequence;
    friend class ::testing::internal::ExpectationBase;
    friend class ::testing::internal::UntypedFunctionMockerBase;

    template<typename F>
    friend class ::testing::internal::FunctionMockerBase;

    template<typename F>
    friend class ::testing::internal::TypedExpectation;

    // This comparator is needed for putting Expectation objects into a set.
    class Less
    {
    public:
        bool operator()(const Expectation &lhs, const Expectation &rhs) const
        {
            return lhs.expectation_base_.get() < rhs.expectation_base_.get();
        }
    };

    typedef ::std::set<Expectation, Less> Set;

    Expectation(
        const internal::linked_ptr<internal::ExpectationBase> &expectation_base);

    // Returns the expectation this object references.
    const internal::linked_ptr<internal::ExpectationBase> &
    expectation_base() const
    {
        return expectation_base_;
    }

    // A linked_ptr that co-owns the expectation this handle references.
    internal::linked_ptr<internal::ExpectationBase> expectation_base_;
};

// A set of expectation handles.  Useful in the .After() clause of
// EXPECT_CALL() for setting the (partial) order of expectations.  The
// syntax:
//
//   ExpectationSet es;
//   es += EXPECT_CALL(...)...;
//   es += EXPECT_CALL(...)...;
//   EXPECT_CALL(...).After(es)...;
//
// sets three expectations where the last one can only be matched
// after the first two have both been satisfied.
//
// This class is copyable and has value semantics.
class ExpectationSet
{
public:
    // A bidirectional iterator that can read a const element in the set.
    typedef Expectation::Set::const_iterator const_iterator;

    // An object stored in the set.  This is an alias of Expectation.
    typedef Expectation::Set::value_type value_type;

    // Constructs an empty set.
    ExpectationSet() {}

    // This single-argument ctor must not be explicit, in order to support the
    //   ExpectationSet es = EXPECT_CALL(...);
    // syntax.
    ExpectationSet(internal::ExpectationBase &exp)
    { // NOLINT
        *this += Expectation(exp);
    }

    // This single-argument ctor implements implicit conversion from
    // Expectation and thus must not be explicit.  This allows either an
    // Expectation or an ExpectationSet to be used in .After().
    ExpectationSet(const Expectation &e)
    { // NOLINT
        *this += e;
    }

    // The compiler-generator ctor and operator= works exactly as
    // intended, so we don't need to define our own.

    // Returns true iff rhs contains the same set of Expectation objects
    // as this does.
    bool operator==(const ExpectationSet &rhs) const
    {
        return expectations_ == rhs.expectations_;
    }

    bool operator!=(const ExpectationSet &rhs) const { return !(*this == rhs); }

    // Implements the syntax
    //   expectation_set += EXPECT_CALL(...);
    ExpectationSet &operator+=(const Expectation &e)
    {
        expectations_.insert(e);
        return *this;
    }

    int size() const { return static_cast<int>(expectations_.size()); }

    const_iterator begin() const { return expectations_.begin(); }
    const_iterator end() const { return expectations_.end(); }

private:
    Expectation::Set expectations_;
};

// Sequence objects are used by a user to specify the relative order
// in which the expectations should match.  They are copyable (we rely
// on the compiler-defined copy constructor and assignment operator).
class GTEST_API_ Sequence
{
public:
    // Constructs an empty sequence.
    Sequence()
        : last_expectation_(new Expectation)
    {
    }

    // Adds an expectation to this sequence.  The caller must ensure
    // that no other thread is accessing this Sequence object.
    void AddExpectation(const Expectation &expectation) const;

private:
    // The last expectation in this sequence.  We use a linked_ptr here
    // because Sequence objects are copyable and we want the copies to
    // be aliases.  The linked_ptr allows the copies to co-own and share
    // the same Expectation object.
    internal::linked_ptr<Expectation> last_expectation_;
}; // class Sequence

// An object of this type causes all EXPECT_CALL() statements
// encountered in its scope to be put in an anonymous sequence.  The
// work is done in the constructor and destructor.  You should only
// create an InSequence object on the stack.
//
// The sole purpose for this class is to support easy definition of
// sequential expectations, e.g.
//
//   {
//     InSequence dummy;  // The name of the object doesn't matter.
//
//     // The following expectations must match in the order they appear.
//     EXPECT_CALL(a, Bar())...;
//     EXPECT_CALL(a, Baz())...;
//     ...
//     EXPECT_CALL(b, Xyz())...;
//   }
//
// You can create InSequence objects in multiple threads, as long as
// they are used to affect different mock objects.  The idea is that
// each thread can create and set up its own mocks as if it's the only
// thread.  However, for clarity of your tests we recommend you to set
// up mocks in the main thread unless you have a good reason not to do
// so.
class GTEST_API_ InSequence
{
public:
    InSequence();
    ~InSequence();

private:
    bool sequence_created_;

    GTEST_DISALLOW_COPY_AND_ASSIGN_(InSequence); // NOLINT
} GTEST_ATTRIBUTE_UNUSED_;

namespace internal {

// Points to the implicit sequence introduced by a living InSequence
// object (if any) in the current thread or NULL.
GTEST_API_ extern ThreadLocal<Sequence *> g_gmock_implicit_sequence;

// Base class for implementing expectations.
//
// There are two reasons for having a type-agnostic base class for
// Expectation:
//
//   1. We need to store collections of expectations of different
//   types (e.g. all pre-requisites of a particular expectation, all
//   expectations in a sequence).  Therefore these expectation objects
//   must share a common base class.
//
//   2. We can avoid binary code bloat by moving methods not depending
//   on the template argument of Expectation to the base class.
//
// This class is internal and mustn't be used by user code directly.
class GTEST_API_ ExpectationBase
{
public:
    // source_text is the EXPECT_CALL(...) source that created this Expectation.
    ExpectationBase(const char *file, int line, const std::string &source_text);

    virtual ~ExpectationBase();

    // Where in the source file was the expectation spec defined?
    const char *file() const { return file_; }
    int line() const { return line_; }
    const char *source_text() const { return source_text_.c_str(); }
    // Returns the cardinality specified in the expectation spec.
    const Cardinality &cardinality() const { return cardinality_; }

    // Describes the source file location of this expectation.
    void DescribeLocationTo(::std::ostream *os) const
    {
        *os << FormatFileLocation(file(), line()) << " ";
    }

    // Describes how many times a function call matching this
    // expectation has occurred.
    void DescribeCallCountTo(::std::ostream *os) const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);

    // If this mock method has an extra matcher (i.e. .With(matcher)),
    // describes it to the ostream.
    virtual void MaybeDescribeExtraMatcherTo(::std::ostream *os) = 0;

protected:
    friend class ::testing::Expectation;
    friend class UntypedFunctionMockerBase;

    enum Clause {
        // Don't change the order of the enum members!
        kNone,
        kWith,
        kTimes,
        kInSequence,
        kAfter,
        kWillOnce,
        kWillRepeatedly,
        kRetiresOnSaturation
    };

    typedef std::vector<const void *> UntypedActions;

    // Returns an Expectation object that references and co-owns this
    // expectation.
    virtual Expectation GetHandle() = 0;

    // Asserts that the EXPECT_CALL() statement has the given property.
    void AssertSpecProperty(bool property,
                            const std::string &failure_message) const
    {
        Assert(property, file_, line_, failure_message);
    }

    // Expects that the EXPECT_CALL() statement has the given property.
    void ExpectSpecProperty(bool property,
                            const std::string &failure_message) const
    {
        Expect(property, file_, line_, failure_message);
    }

    // Explicitly specifies the cardinality of this expectation.  Used
    // by the subclasses to implement the .Times() clause.
    void SpecifyCardinality(const Cardinality &cardinality);

    // Returns true iff the user specified the cardinality explicitly
    // using a .Times().
    bool cardinality_specified() const { return cardinality_specified_; }

    // Sets the cardinality of this expectation spec.
    void set_cardinality(const Cardinality &a_cardinality)
    {
        cardinality_ = a_cardinality;
    }

    // The following group of methods should only be called after the
    // EXPECT_CALL() statement, and only when g_gmock_mutex is held by
    // the current thread.

    // Retires all pre-requisites of this expectation.
    void RetireAllPreRequisites()
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);

    // Returns true iff this expectation is retired.
    bool is_retired() const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        return retired_;
    }

    // Retires this expectation.
    void Retire()
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        retired_ = true;
    }

    // Returns true iff this expectation is satisfied.
    bool IsSatisfied() const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        return cardinality().IsSatisfiedByCallCount(call_count_);
    }

    // Returns true iff this expectation is saturated.
    bool IsSaturated() const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        return cardinality().IsSaturatedByCallCount(call_count_);
    }

    // Returns true iff this expectation is over-saturated.
    bool IsOverSaturated() const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        return cardinality().IsOverSaturatedByCallCount(call_count_);
    }

    // Returns true iff all pre-requisites of this expectation are satisfied.
    bool AllPrerequisitesAreSatisfied() const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);

    // Adds unsatisfied pre-requisites of this expectation to 'result'.
    void FindUnsatisfiedPrerequisites(ExpectationSet *result) const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);

    // Returns the number this expectation has been invoked.
    int call_count() const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        return call_count_;
    }

    // Increments the number this expectation has been invoked.
    void IncrementCallCount()
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        call_count_++;
    }

    // Checks the action count (i.e. the number of WillOnce() and
    // WillRepeatedly() clauses) against the cardinality if this hasn't
    // been done before.  Prints a warning if there are too many or too
    // few actions.
    void CheckActionCountIfNotDone() const
        GTEST_LOCK_EXCLUDED_(mutex_);

    friend class ::testing::Sequence;
    friend class ::testing::internal::ExpectationTester;

    template<typename Function>
    friend class TypedExpectation;

    // Implements the .Times() clause.
    void UntypedTimes(const Cardinality &a_cardinality);

    // This group of fields are part of the spec and won't change after
    // an EXPECT_CALL() statement finishes.
    const char *file_; // The file that contains the expectation.
    int line_; // The line number of the expectation.
    const std::string source_text_; // The EXPECT_CALL(...) source text.
    // True iff the cardinality is specified explicitly.
    bool cardinality_specified_;
    Cardinality cardinality_; // The cardinality of the expectation.
    // The immediate pre-requisites (i.e. expectations that must be
    // satisfied before this expectation can be matched) of this
    // expectation.  We use linked_ptr in the set because we want an
    // Expectation object to be co-owned by its FunctionMocker and its
    // successors.  This allows multiple mock objects to be deleted at
    // different times.
    ExpectationSet immediate_prerequisites_;

    // This group of fields are the current state of the expectation,
    // and can change as the mock function is called.
    int call_count_; // How many times this expectation has been invoked.
    bool retired_; // True iff this expectation has retired.
    UntypedActions untyped_actions_;
    bool extra_matcher_specified_;
    bool repeated_action_specified_; // True if a WillRepeatedly() was specified.
    bool retires_on_saturation_;
    Clause last_clause_;
    mutable bool action_count_checked_; // Under mutex_.
    mutable Mutex mutex_; // Protects action_count_checked_.

    GTEST_DISALLOW_ASSIGN_(ExpectationBase);
}; // class ExpectationBase

// Impements an expectation for the given function type.
template<typename F>
class TypedExpectation : public ExpectationBase
{
public:
    typedef typename Function<F>::ArgumentTuple ArgumentTuple;
    typedef typename Function<F>::ArgumentMatcherTuple ArgumentMatcherTuple;
    typedef typename Function<F>::Result Result;

    TypedExpectation(FunctionMockerBase<F> *owner, const char *a_file, int a_line,
                     const std::string &a_source_text,
                     const ArgumentMatcherTuple &m)
        : ExpectationBase(a_file, a_line, a_source_text)
        , owner_(owner)
        , matchers_(m)
        ,
        // By default, extra_matcher_ should match anything.  However,
        // we cannot initialize it with _ as that triggers a compiler
        // bug in Symbian's C++ compiler (cannot decide between two
        // overloaded constructors of Matcher<const ArgumentTuple&>).
        extra_matcher_(A<const ArgumentTuple &>())
        , repeated_action_(DoDefault())
    {
    }

    virtual ~TypedExpectation()
    {
        // Check the validity of the action count if it hasn't been done
        // yet (for example, if the expectation was never used).
        CheckActionCountIfNotDone();
        for (UntypedActions::const_iterator it = untyped_actions_.begin();
             it != untyped_actions_.end(); ++it) {
            delete static_cast<const Action<F> *>(*it);
        }
    }

    // Implements the .With() clause.
    TypedExpectation &With(const Matcher<const ArgumentTuple &> &m)
    {
        if (last_clause_ == kWith) {
            ExpectSpecProperty(false,
                               ".With() cannot appear "
                               "more than once in an EXPECT_CALL().");
        } else {
            ExpectSpecProperty(last_clause_ < kWith,
                               ".With() must be the first "
                               "clause in an EXPECT_CALL().");
        }
        last_clause_ = kWith;

        extra_matcher_ = m;
        extra_matcher_specified_ = true;
        return *this;
    }

    // Implements the .Times() clause.
    TypedExpectation &Times(const Cardinality &a_cardinality)
    {
        ExpectationBase::UntypedTimes(a_cardinality);
        return *this;
    }

    // Implements the .Times() clause.
    TypedExpectation &Times(int n)
    {
        return Times(Exactly(n));
    }

    // Implements the .InSequence() clause.
    TypedExpectation &InSequence(const Sequence &s)
    {
        ExpectSpecProperty(last_clause_ <= kInSequence,
                           ".InSequence() cannot appear after .After(),"
                           " .WillOnce(), .WillRepeatedly(), or "
                           ".RetiresOnSaturation().");
        last_clause_ = kInSequence;

        s.AddExpectation(GetHandle());
        return *this;
    }
    TypedExpectation &InSequence(const Sequence &s1, const Sequence &s2)
    {
        return InSequence(s1).InSequence(s2);
    }
    TypedExpectation &InSequence(const Sequence &s1, const Sequence &s2,
                                 const Sequence &s3)
    {
        return InSequence(s1, s2).InSequence(s3);
    }
    TypedExpectation &InSequence(const Sequence &s1, const Sequence &s2,
                                 const Sequence &s3, const Sequence &s4)
    {
        return InSequence(s1, s2, s3).InSequence(s4);
    }
    TypedExpectation &InSequence(const Sequence &s1, const Sequence &s2,
                                 const Sequence &s3, const Sequence &s4,
                                 const Sequence &s5)
    {
        return InSequence(s1, s2, s3, s4).InSequence(s5);
    }

    // Implements that .After() clause.
    TypedExpectation &After(const ExpectationSet &s)
    {
        ExpectSpecProperty(last_clause_ <= kAfter,
                           ".After() cannot appear after .WillOnce(),"
                           " .WillRepeatedly(), or "
                           ".RetiresOnSaturation().");
        last_clause_ = kAfter;

        for (ExpectationSet::const_iterator it = s.begin(); it != s.end(); ++it) {
            immediate_prerequisites_ += *it;
        }
        return *this;
    }
    TypedExpectation &After(const ExpectationSet &s1, const ExpectationSet &s2)
    {
        return After(s1).After(s2);
    }
    TypedExpectation &After(const ExpectationSet &s1, const ExpectationSet &s2,
                            const ExpectationSet &s3)
    {
        return After(s1, s2).After(s3);
    }
    TypedExpectation &After(const ExpectationSet &s1, const ExpectationSet &s2,
                            const ExpectationSet &s3, const ExpectationSet &s4)
    {
        return After(s1, s2, s3).After(s4);
    }
    TypedExpectation &After(const ExpectationSet &s1, const ExpectationSet &s2,
                            const ExpectationSet &s3, const ExpectationSet &s4,
                            const ExpectationSet &s5)
    {
        return After(s1, s2, s3, s4).After(s5);
    }

    // Implements the .WillOnce() clause.
    TypedExpectation &WillOnce(const Action<F> &action)
    {
        ExpectSpecProperty(last_clause_ <= kWillOnce,
                           ".WillOnce() cannot appear after "
                           ".WillRepeatedly() or .RetiresOnSaturation().");
        last_clause_ = kWillOnce;

        untyped_actions_.push_back(new Action<F>(action));
        if (!cardinality_specified()) {
            set_cardinality(Exactly(static_cast<int>(untyped_actions_.size())));
        }
        return *this;
    }

    // Implements the .WillRepeatedly() clause.
    TypedExpectation &WillRepeatedly(const Action<F> &action)
    {
        if (last_clause_ == kWillRepeatedly) {
            ExpectSpecProperty(false,
                               ".WillRepeatedly() cannot appear "
                               "more than once in an EXPECT_CALL().");
        } else {
            ExpectSpecProperty(last_clause_ < kWillRepeatedly,
                               ".WillRepeatedly() cannot appear "
                               "after .RetiresOnSaturation().");
        }
        last_clause_ = kWillRepeatedly;
        repeated_action_specified_ = true;

        repeated_action_ = action;
        if (!cardinality_specified()) {
            set_cardinality(AtLeast(static_cast<int>(untyped_actions_.size())));
        }

        // Now that no more action clauses can be specified, we check
        // whether their count makes sense.
        CheckActionCountIfNotDone();
        return *this;
    }

    // Implements the .RetiresOnSaturation() clause.
    TypedExpectation &RetiresOnSaturation()
    {
        ExpectSpecProperty(last_clause_ < kRetiresOnSaturation,
                           ".RetiresOnSaturation() cannot appear "
                           "more than once.");
        last_clause_ = kRetiresOnSaturation;
        retires_on_saturation_ = true;

        // Now that no more action clauses can be specified, we check
        // whether their count makes sense.
        CheckActionCountIfNotDone();
        return *this;
    }

    // Returns the matchers for the arguments as specified inside the
    // EXPECT_CALL() macro.
    const ArgumentMatcherTuple &matchers() const
    {
        return matchers_;
    }

    // Returns the matcher specified by the .With() clause.
    const Matcher<const ArgumentTuple &> &extra_matcher() const
    {
        return extra_matcher_;
    }

    // Returns the action specified by the .WillRepeatedly() clause.
    const Action<F> &repeated_action() const { return repeated_action_; }

    // If this mock method has an extra matcher (i.e. .With(matcher)),
    // describes it to the ostream.
    virtual void MaybeDescribeExtraMatcherTo(::std::ostream *os)
    {
        if (extra_matcher_specified_) {
            *os << "    Expected args: ";
            extra_matcher_.DescribeTo(os);
            *os << "\n";
        }
    }

private:
    template<typename Function>
    friend class FunctionMockerBase;

    // Returns an Expectation object that references and co-owns this
    // expectation.
    virtual Expectation GetHandle()
    {
        return owner_->GetHandleOf(this);
    }

    // The following methods will be called only after the EXPECT_CALL()
    // statement finishes and when the current thread holds
    // g_gmock_mutex.

    // Returns true iff this expectation matches the given arguments.
    bool Matches(const ArgumentTuple &args) const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        return TupleMatches(matchers_, args) && extra_matcher_.Matches(args);
    }

    // Returns true iff this expectation should handle the given arguments.
    bool ShouldHandleArguments(const ArgumentTuple &args) const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();

        // In case the action count wasn't checked when the expectation
        // was defined (e.g. if this expectation has no WillRepeatedly()
        // or RetiresOnSaturation() clause), we check it when the
        // expectation is used for the first time.
        CheckActionCountIfNotDone();
        return !is_retired() && AllPrerequisitesAreSatisfied() && Matches(args);
    }

    // Describes the result of matching the arguments against this
    // expectation to the given ostream.
    void ExplainMatchResultTo(
        const ArgumentTuple &args,
        ::std::ostream *os) const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();

        if (is_retired()) {
            *os << "         Expected: the expectation is active\n"
                << "           Actual: it is retired\n";
        } else if (!Matches(args)) {
            if (!TupleMatches(matchers_, args)) {
                ExplainMatchFailureTupleTo(matchers_, args, os);
            }
            StringMatchResultListener listener;
            if (!extra_matcher_.MatchAndExplain(args, &listener)) {
                *os << "    Expected args: ";
                extra_matcher_.DescribeTo(os);
                *os << "\n           Actual: don't match";

                internal::PrintIfNotEmpty(listener.str(), os);
                *os << "\n";
            }
        } else if (!AllPrerequisitesAreSatisfied()) {
            *os << "         Expected: all pre-requisites are satisfied\n"
                << "           Actual: the following immediate pre-requisites "
                << "are not satisfied:\n";
            ExpectationSet unsatisfied_prereqs;
            FindUnsatisfiedPrerequisites(&unsatisfied_prereqs);
            int i = 0;
            for (ExpectationSet::const_iterator it = unsatisfied_prereqs.begin();
                 it != unsatisfied_prereqs.end(); ++it) {
                it->expectation_base()->DescribeLocationTo(os);
                *os << "pre-requisite #" << i++ << "\n";
            }
            *os << "                   (end of pre-requisites)\n";
        } else {
            // This line is here just for completeness' sake.  It will never
            // be executed as currently the ExplainMatchResultTo() function
            // is called only when the mock function call does NOT match the
            // expectation.
            *os << "The call matches the expectation.\n";
        }
    }

    // Returns the action that should be taken for the current invocation.
    const Action<F> &GetCurrentAction(
        const FunctionMockerBase<F> *mocker,
        const ArgumentTuple &args) const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        const int count = call_count();
        Assert(count >= 1, __FILE__, __LINE__,
               "call_count() is <= 0 when GetCurrentAction() is "
               "called - this should never happen.");

        const int action_count = static_cast<int>(untyped_actions_.size());
        if (action_count > 0 && !repeated_action_specified_ && count > action_count) {
            // If there is at least one WillOnce() and no WillRepeatedly(),
            // we warn the user when the WillOnce() clauses ran out.
            ::std::stringstream ss;
            DescribeLocationTo(&ss);
            ss << "Actions ran out in " << source_text() << "...\n"
               << "Called " << count << " times, but only "
               << action_count << " WillOnce()"
               << (action_count == 1 ? " is" : "s are") << " specified - ";
            mocker->DescribeDefaultActionTo(args, &ss);
            Log(kWarning, ss.str(), 1);
        }

        return count <= action_count ? *static_cast<const Action<F> *>(untyped_actions_[count - 1]) : repeated_action();
    }

    // Given the arguments of a mock function call, if the call will
    // over-saturate this expectation, returns the default action;
    // otherwise, returns the next action in this expectation.  Also
    // describes *what* happened to 'what', and explains *why* Google
    // Mock does it to 'why'.  This method is not const as it calls
    // IncrementCallCount().  A return value of NULL means the default
    // action.
    const Action<F> *GetActionForArguments(
        const FunctionMockerBase<F> *mocker,
        const ArgumentTuple &args,
        ::std::ostream *what,
        ::std::ostream *why)
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        if (IsSaturated()) {
            // We have an excessive call.
            IncrementCallCount();
            *what << "Mock function called more times than expected - ";
            mocker->DescribeDefaultActionTo(args, what);
            DescribeCallCountTo(why);

            // FIXME: allow the user to control whether
            // unexpected calls should fail immediately or continue using a
            // flag --gmock_unexpected_calls_are_fatal.
            return NULL;
        }

        IncrementCallCount();
        RetireAllPreRequisites();

        if (retires_on_saturation_ && IsSaturated()) {
            Retire();
        }

        // Must be done after IncrementCount()!
        *what << "Mock function call matches " << source_text() << "...\n";
        return &(GetCurrentAction(mocker, args));
    }

    // All the fields below won't change once the EXPECT_CALL()
    // statement finishes.
    FunctionMockerBase<F> *const owner_;
    ArgumentMatcherTuple matchers_;
    Matcher<const ArgumentTuple &> extra_matcher_;
    Action<F> repeated_action_;

    GTEST_DISALLOW_COPY_AND_ASSIGN_(TypedExpectation);
}; // class TypedExpectation

// A MockSpec object is used by ON_CALL() or EXPECT_CALL() for
// specifying the default behavior of, or expectation on, a mock
// function.

// Note: class MockSpec really belongs to the ::testing namespace.
// However if we define it in ::testing, MSVC will complain when
// classes in ::testing::internal declare it as a friend class
// template.  To workaround this compiler bug, we define MockSpec in
// ::testing::internal and import it into ::testing.

// Logs a message including file and line number information.
GTEST_API_ void LogWithLocation(testing::internal::LogSeverity severity,
                                const char *file, int line,
                                const std::string &message);

template<typename F>
class MockSpec
{
public:
    typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
    typedef typename internal::Function<F>::ArgumentMatcherTuple
        ArgumentMatcherTuple;

    // Constructs a MockSpec object, given the function mocker object
    // that the spec is associated with.
    MockSpec(internal::FunctionMockerBase<F> *function_mocker,
             const ArgumentMatcherTuple &matchers)
        : function_mocker_(function_mocker)
        , matchers_(matchers)
    {
    }

    // Adds a new default action spec to the function mocker and returns
    // the newly created spec.
    internal::OnCallSpec<F> &InternalDefaultActionSetAt(
        const char *file, int line, const char *obj, const char *call)
    {
        LogWithLocation(internal::kInfo, file, line,
                        std::string("ON_CALL(") + obj + ", " + call + ") invoked");
        return function_mocker_->AddNewOnCallSpec(file, line, matchers_);
    }

    // Adds a new expectation spec to the function mocker and returns
    // the newly created spec.
    internal::TypedExpectation<F> &InternalExpectedAt(
        const char *file, int line, const char *obj, const char *call)
    {
        const std::string source_text(std::string("EXPECT_CALL(") + obj + ", " + call + ")");
        LogWithLocation(internal::kInfo, file, line, source_text + " invoked");
        return function_mocker_->AddNewExpectation(
            file, line, source_text, matchers_);
    }

    // This operator overload is used to swallow the superfluous parameter list
    // introduced by the ON/EXPECT_CALL macros. See the macro comments for more
    // explanation.
    MockSpec<F> &operator()(const internal::WithoutMatchers &, void *const)
    {
        return *this;
    }

private:
    template<typename Function>
    friend class internal::FunctionMocker;

    // The function mocker that owns this spec.
    internal::FunctionMockerBase<F> *const function_mocker_;
    // The argument matchers specified in the spec.
    ArgumentMatcherTuple matchers_;

    GTEST_DISALLOW_ASSIGN_(MockSpec);
}; // class MockSpec

// Wrapper type for generically holding an ordinary value or lvalue reference.
// If T is not a reference type, it must be copyable or movable.
// ReferenceOrValueWrapper<T> is movable, and will also be copyable unless
// T is a move-only value type (which means that it will always be copyable
// if the current platform does not support move semantics).
//
// The primary template defines handling for values, but function header
// comments describe the contract for the whole template (including
// specializations).
template<typename T>
class ReferenceOrValueWrapper
{
public:
    // Constructs a wrapper from the given value/reference.
    explicit ReferenceOrValueWrapper(T value)
        : value_(::testing::internal::move(value))
    {
    }

    // Unwraps and returns the underlying value/reference, exactly as
    // originally passed. The behavior of calling this more than once on
    // the same object is unspecified.
    T Unwrap() { return ::testing::internal::move(value_); }

    // Provides nondestructive access to the underlying value/reference.
    // Always returns a const reference (more precisely,
    // const RemoveReference<T>&). The behavior of calling this after
    // calling Unwrap on the same object is unspecified.
    const T &Peek() const
    {
        return value_;
    }

private:
    T value_;
};

// Specialization for lvalue reference types. See primary template
// for documentation.
template<typename T>
class ReferenceOrValueWrapper<T &>
{
public:
    // Workaround for debatable pass-by-reference lint warning (c-library-team
    // policy precludes NOLINT in this context)
    typedef T &reference;
    explicit ReferenceOrValueWrapper(reference ref)
        : value_ptr_(&ref)
    {
    }
    T &Unwrap() { return *value_ptr_; }
    const T &Peek() const { return *value_ptr_; }

private:
    T *value_ptr_;
};

// MSVC warns about using 'this' in base member initializer list, so
// we need to temporarily disable the warning.  We have to do it for
// the entire class to suppress the warning, even though it's about
// the constructor only.
GTEST_DISABLE_MSC_WARNINGS_PUSH_(4355)

// C++ treats the void type specially.  For example, you cannot define
// a void-typed variable or pass a void value to a function.
// ActionResultHolder<T> holds a value of type T, where T must be a
// copyable type or void (T doesn't need to be default-constructable).
// It hides the syntactic difference between void and other types, and
// is used to unify the code for invoking both void-returning and
// non-void-returning mock functions.

// Untyped base class for ActionResultHolder<T>.
class UntypedActionResultHolderBase
{
public:
    virtual ~UntypedActionResultHolderBase() {}

    // Prints the held value as an action's result to os.
    virtual void PrintAsActionResult(::std::ostream *os) const = 0;
};

// This generic definition is used when T is not void.
template<typename T>
class ActionResultHolder : public UntypedActionResultHolderBase
{
public:
    // Returns the held value. Must not be called more than once.
    T Unwrap()
    {
        return result_.Unwrap();
    }

    // Prints the held value as an action's result to os.
    virtual void PrintAsActionResult(::std::ostream *os) const
    {
        *os << "\n          Returns: ";
        // T may be a reference type, so we don't use UniversalPrint().
        UniversalPrinter<T>::Print(result_.Peek(), os);
    }

    // Performs the given mock function's default action and returns the
    // result in a new-ed ActionResultHolder.
    template<typename F>
    static ActionResultHolder *PerformDefaultAction(
        const FunctionMockerBase<F> *func_mocker,
        typename RvalueRef<typename Function<F>::ArgumentTuple>::type args,
        const std::string &call_description)
    {
        return new ActionResultHolder(Wrapper(func_mocker->PerformDefaultAction(
            internal::move(args), call_description)));
    }

    // Performs the given action and returns the result in a new-ed
    // ActionResultHolder.
    template<typename F>
    static ActionResultHolder *PerformAction(
        const Action<F> &action,
        typename RvalueRef<typename Function<F>::ArgumentTuple>::type args)
    {
        return new ActionResultHolder(
            Wrapper(action.Perform(internal::move(args))));
    }

private:
    typedef ReferenceOrValueWrapper<T> Wrapper;

    explicit ActionResultHolder(Wrapper result)
        : result_(::testing::internal::move(result))
    {
    }

    Wrapper result_;

    GTEST_DISALLOW_COPY_AND_ASSIGN_(ActionResultHolder);
};

// Specialization for T = void.
template<>
class ActionResultHolder<void> : public UntypedActionResultHolderBase
{
public:
    void Unwrap() {}

    virtual void PrintAsActionResult(::std::ostream * /* os */) const {}

    // Performs the given mock function's default action and returns ownership
    // of an empty ActionResultHolder*.
    template<typename F>
    static ActionResultHolder *PerformDefaultAction(
        const FunctionMockerBase<F> *func_mocker,
        typename RvalueRef<typename Function<F>::ArgumentTuple>::type args,
        const std::string &call_description)
    {
        func_mocker->PerformDefaultAction(internal::move(args), call_description);
        return new ActionResultHolder;
    }

    // Performs the given action and returns ownership of an empty
    // ActionResultHolder*.
    template<typename F>
    static ActionResultHolder *PerformAction(
        const Action<F> &action,
        typename RvalueRef<typename Function<F>::ArgumentTuple>::type args)
    {
        action.Perform(internal::move(args));
        return new ActionResultHolder;
    }

private:
    ActionResultHolder() {}
    GTEST_DISALLOW_COPY_AND_ASSIGN_(ActionResultHolder);
};

// The base of the function mocker class for the given function type.
// We put the methods in this class instead of its child to avoid code
// bloat.
template<typename F>
class FunctionMockerBase : public UntypedFunctionMockerBase
{
public:
    typedef typename Function<F>::Result Result;
    typedef typename Function<F>::ArgumentTuple ArgumentTuple;
    typedef typename Function<F>::ArgumentMatcherTuple ArgumentMatcherTuple;

    FunctionMockerBase() {}

    // The destructor verifies that all expectations on this mock
    // function have been satisfied.  If not, it will report Google Test
    // non-fatal failures for the violations.
    virtual ~FunctionMockerBase()
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex)
    {
        MutexLock l(&g_gmock_mutex);
        VerifyAndClearExpectationsLocked();
        Mock::UnregisterLocked(this);
        ClearDefaultActionsLocked();
    }

    // Returns the ON_CALL spec that matches this mock function with the
    // given arguments; returns NULL if no matching ON_CALL is found.
    // L = *
    const OnCallSpec<F> *FindOnCallSpec(
        const ArgumentTuple &args) const
    {
        for (UntypedOnCallSpecs::const_reverse_iterator it = untyped_on_call_specs_.rbegin();
             it != untyped_on_call_specs_.rend(); ++it) {
            const OnCallSpec<F> *spec = static_cast<const OnCallSpec<F> *>(*it);
            if (spec->Matches(args))
                return spec;
        }

        return NULL;
    }

    // Performs the default action of this mock function on the given
    // arguments and returns the result. Asserts (or throws if
    // exceptions are enabled) with a helpful call descrption if there
    // is no valid return value. This method doesn't depend on the
    // mutable state of this object, and thus can be called concurrently
    // without locking.
    // L = *
    Result PerformDefaultAction(
        typename RvalueRef<typename Function<F>::ArgumentTuple>::type args,
        const std::string &call_description) const
    {
        const OnCallSpec<F> *const spec =
            this->FindOnCallSpec(args);
        if (spec != NULL) {
            return spec->GetAction().Perform(internal::move(args));
        }
        const std::string message =
            call_description + "\n    The mock function has no default action "
                               "set, and its return type has no default value set.";
#if GTEST_HAS_EXCEPTIONS
        if (!DefaultValue<Result>::Exists()) {
            throw std::runtime_error(message);
        }
#else
        Assert(DefaultValue<Result>::Exists(), "", -1, message);
#endif
        return DefaultValue<Result>::Get();
    }

    // Performs the default action with the given arguments and returns
    // the action's result.  The call description string will be used in
    // the error message to describe the call in the case the default
    // action fails.  The caller is responsible for deleting the result.
    // L = *
    virtual UntypedActionResultHolderBase *UntypedPerformDefaultAction(
        void *untyped_args, // must point to an ArgumentTuple
        const std::string &call_description) const
    {
        ArgumentTuple *args = static_cast<ArgumentTuple *>(untyped_args);
        return ResultHolder::PerformDefaultAction(this, internal::move(*args),
                                                  call_description);
    }

    // Performs the given action with the given arguments and returns
    // the action's result.  The caller is responsible for deleting the
    // result.
    // L = *
    virtual UntypedActionResultHolderBase *UntypedPerformAction(
        const void *untyped_action, void *untyped_args) const
    {
        // Make a copy of the action before performing it, in case the
        // action deletes the mock object (and thus deletes itself).
        const Action<F> action = *static_cast<const Action<F> *>(untyped_action);
        ArgumentTuple *args = static_cast<ArgumentTuple *>(untyped_args);
        return ResultHolder::PerformAction(action, internal::move(*args));
    }

    // Implements UntypedFunctionMockerBase::ClearDefaultActionsLocked():
    // clears the ON_CALL()s set on this mock function.
    virtual void ClearDefaultActionsLocked()
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();

        // Deleting our default actions may trigger other mock objects to be
        // deleted, for example if an action contains a reference counted smart
        // pointer to that mock object, and that is the last reference. So if we
        // delete our actions within the context of the global mutex we may deadlock
        // when this method is called again. Instead, make a copy of the set of
        // actions to delete, clear our set within the mutex, and then delete the
        // actions outside of the mutex.
        UntypedOnCallSpecs specs_to_delete;
        untyped_on_call_specs_.swap(specs_to_delete);

        g_gmock_mutex.Unlock();
        for (UntypedOnCallSpecs::const_iterator it =
                 specs_to_delete.begin();
             it != specs_to_delete.end(); ++it) {
            delete static_cast<const OnCallSpec<F> *>(*it);
        }

        // Lock the mutex again, since the caller expects it to be locked when we
        // return.
        g_gmock_mutex.Lock();
    }

protected:
    template<typename Function>
    friend class MockSpec;

    typedef ActionResultHolder<Result> ResultHolder;

    // Returns the result of invoking this mock function with the given
    // arguments.  This function can be safely called from multiple
    // threads concurrently.
    Result InvokeWith(
        typename RvalueRef<typename Function<F>::ArgumentTuple>::type args)
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex)
    {
        // const_cast is required since in C++98 we still pass ArgumentTuple around
        // by const& instead of rvalue reference.
        void *untyped_args = const_cast<void *>(static_cast<const void *>(&args));
        scoped_ptr<ResultHolder> holder(
            DownCast_<ResultHolder *>(this->UntypedInvokeWith(untyped_args)));
        return holder->Unwrap();
    }

    // Adds and returns a default action spec for this mock function.
    OnCallSpec<F> &AddNewOnCallSpec(
        const char *file, int line,
        const ArgumentMatcherTuple &m)
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex)
    {
        Mock::RegisterUseByOnCallOrExpectCall(MockObject(), file, line);
        OnCallSpec<F> *const on_call_spec = new OnCallSpec<F>(file, line, m);
        untyped_on_call_specs_.push_back(on_call_spec);
        return *on_call_spec;
    }

    // Adds and returns an expectation spec for this mock function.
    TypedExpectation<F> &AddNewExpectation(const char *file, int line,
                                           const std::string &source_text,
                                           const ArgumentMatcherTuple &m)
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex)
    {
        Mock::RegisterUseByOnCallOrExpectCall(MockObject(), file, line);
        TypedExpectation<F> *const expectation =
            new TypedExpectation<F>(this, file, line, source_text, m);
        const linked_ptr<ExpectationBase> untyped_expectation(expectation);
        // See the definition of untyped_expectations_ for why access to
        // it is unprotected here.
        untyped_expectations_.push_back(untyped_expectation);

        // Adds this expectation into the implicit sequence if there is one.
        Sequence *const implicit_sequence = g_gmock_implicit_sequence.get();
        if (implicit_sequence != NULL) {
            implicit_sequence->AddExpectation(Expectation(untyped_expectation));
        }

        return *expectation;
    }

private:
    template<typename Func>
    friend class TypedExpectation;

    // Some utilities needed for implementing UntypedInvokeWith().

    // Describes what default action will be performed for the given
    // arguments.
    // L = *
    void DescribeDefaultActionTo(const ArgumentTuple &args,
                                 ::std::ostream *os) const
    {
        const OnCallSpec<F> *const spec = FindOnCallSpec(args);

        if (spec == NULL) {
            *os << (internal::type_equals<Result, void>::value ? "returning directly.\n" : "returning default value.\n");
        } else {
            *os << "taking default action specified at:\n"
                << FormatFileLocation(spec->file(), spec->line()) << "\n";
        }
    }

    // Writes a message that the call is uninteresting (i.e. neither
    // explicitly expected nor explicitly unexpected) to the given
    // ostream.
    virtual void UntypedDescribeUninterestingCall(
        const void *untyped_args,
        ::std::ostream *os) const
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex)
    {
        const ArgumentTuple &args =
            *static_cast<const ArgumentTuple *>(untyped_args);
        *os << "Uninteresting mock function call - ";
        DescribeDefaultActionTo(args, os);
        *os << "    Function call: " << Name();
        UniversalPrint(args, os);
    }

    // Returns the expectation that matches the given function arguments
    // (or NULL is there's no match); when a match is found,
    // untyped_action is set to point to the action that should be
    // performed (or NULL if the action is "do default"), and
    // is_excessive is modified to indicate whether the call exceeds the
    // expected number.
    //
    // Critical section: We must find the matching expectation and the
    // corresponding action that needs to be taken in an ATOMIC
    // transaction.  Otherwise another thread may call this mock
    // method in the middle and mess up the state.
    //
    // However, performing the action has to be left out of the critical
    // section.  The reason is that we have no control on what the
    // action does (it can invoke an arbitrary user function or even a
    // mock function) and excessive locking could cause a dead lock.
    virtual const ExpectationBase *UntypedFindMatchingExpectation(
        const void *untyped_args,
        const void **untyped_action, bool *is_excessive,
        ::std::ostream *what, ::std::ostream *why)
        GTEST_LOCK_EXCLUDED_(g_gmock_mutex)
    {
        const ArgumentTuple &args =
            *static_cast<const ArgumentTuple *>(untyped_args);
        MutexLock l(&g_gmock_mutex);
        TypedExpectation<F> *exp = this->FindMatchingExpectationLocked(args);
        if (exp == NULL) { // A match wasn't found.
            this->FormatUnexpectedCallMessageLocked(args, what, why);
            return NULL;
        }

        // This line must be done before calling GetActionForArguments(),
        // which will increment the call count for *exp and thus affect
        // its saturation status.
        *is_excessive = exp->IsSaturated();
        const Action<F> *action = exp->GetActionForArguments(this, args, what, why);
        if (action != NULL && action->IsDoDefault())
            action = NULL; // Normalize "do default" to NULL.
        *untyped_action = action;
        return exp;
    }

    // Prints the given function arguments to the ostream.
    virtual void UntypedPrintArgs(const void *untyped_args,
                                  ::std::ostream *os) const
    {
        const ArgumentTuple &args =
            *static_cast<const ArgumentTuple *>(untyped_args);
        UniversalPrint(args, os);
    }

    // Returns the expectation that matches the arguments, or NULL if no
    // expectation matches them.
    TypedExpectation<F> *FindMatchingExpectationLocked(
        const ArgumentTuple &args) const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        // See the definition of untyped_expectations_ for why access to
        // it is unprotected here.
        for (typename UntypedExpectations::const_reverse_iterator it =
                 untyped_expectations_.rbegin();
             it != untyped_expectations_.rend(); ++it) {
            TypedExpectation<F> *const exp =
                static_cast<TypedExpectation<F> *>(it->get());
            if (exp->ShouldHandleArguments(args)) {
                return exp;
            }
        }
        return NULL;
    }

    // Returns a message that the arguments don't match any expectation.
    void FormatUnexpectedCallMessageLocked(
        const ArgumentTuple &args,
        ::std::ostream *os,
        ::std::ostream *why) const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        *os << "\nUnexpected mock function call - ";
        DescribeDefaultActionTo(args, os);
        PrintTriedExpectationsLocked(args, why);
    }

    // Prints a list of expectations that have been tried against the
    // current mock function call.
    void PrintTriedExpectationsLocked(
        const ArgumentTuple &args,
        ::std::ostream *why) const
        GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex)
    {
        g_gmock_mutex.AssertHeld();
        const int count = static_cast<int>(untyped_expectations_.size());
        *why << "Google Mock tried the following " << count << " "
             << (count == 1 ? "expectation, but it didn't match" : "expectations, but none matched")
             << ":\n";
        for (int i = 0; i < count; i++) {
            TypedExpectation<F> *const expectation =
                static_cast<TypedExpectation<F> *>(untyped_expectations_[i].get());
            *why << "\n";
            expectation->DescribeLocationTo(why);
            if (count > 1) {
                *why << "tried expectation #" << i << ": ";
            }
            *why << expectation->source_text() << "...\n";
            expectation->ExplainMatchResultTo(args, why);
            expectation->DescribeCallCountTo(why);
        }
    }

    // There is no generally useful and implementable semantics of
    // copying a mock object, so copying a mock is usually a user error.
    // Thus we disallow copying function mockers.  If the user really
    // wants to copy a mock object, they should implement their own copy
    // operation, for example:
    //
    //   class MockFoo : public Foo {
    //    public:
    //     // Defines a copy constructor explicitly.
    //     MockFoo(const MockFoo& src) {}
    //     ...
    //   };
    GTEST_DISALLOW_COPY_AND_ASSIGN_(FunctionMockerBase);
}; // class FunctionMockerBase

GTEST_DISABLE_MSC_WARNINGS_POP_() //  4355

// Implements methods of FunctionMockerBase.

// Verifies that all expectations on this mock function have been
// satisfied.  Reports one or more Google Test non-fatal failures and
// returns false if not.

// Reports an uninteresting call (whose description is in msg) in the
// manner specified by 'reaction'.
void ReportUninterestingCall(CallReaction reaction, const std::string &msg);

} // namespace internal

// The style guide prohibits "using" statements in a namespace scope
// inside a header file.  However, the MockSpec class template is
// meant to be defined in the ::testing namespace.  The following line
// is just a trick for working around a bug in MSVC 8.0, which cannot
// handle it if we define MockSpec in ::testing.
using internal::MockSpec;

// Const(x) is a convenient function for obtaining a const reference
// to x.  This is useful for setting expectations on an overloaded
// const mock method, e.g.
//
//   class MockFoo : public FooInterface {
//    public:
//     MOCK_METHOD0(Bar, int());
//     MOCK_CONST_METHOD0(Bar, int&());
//   };
//
//   MockFoo foo;
//   // Expects a call to non-const MockFoo::Bar().
//   EXPECT_CALL(foo, Bar());
//   // Expects a call to const MockFoo::Bar().
//   EXPECT_CALL(Const(foo), Bar());
template<typename T>
inline const T &Const(const T &x)
{
    return x;
}

// Constructs an Expectation object that references and co-owns exp.
inline Expectation::Expectation(internal::ExpectationBase &exp) // NOLINT
    : expectation_base_(exp.GetHandle().expectation_base())
{
}

} // namespace testing

GTEST_DISABLE_MSC_WARNINGS_POP_() //  4251

// Implementation for ON_CALL and EXPECT_CALL macros. A separate macro is
// required to avoid compile errors when the name of the method used in call is
// a result of macro expansion. See CompilesWithMethodNameExpandedFromMacro
// tests in internal/gmock-spec-builders_test.cc for more details.
//
// This macro supports statements both with and without parameter matchers. If
// the parameter list is omitted, gMock will accept any parameters, which allows
// tests to be written that don't need to encode the number of method
// parameter. This technique may only be used for non-overloaded methods.
//
//   // These are the same:
//   ON_CALL(mock, NoArgsMethod()).WillByDefault(...);
//   ON_CALL(mock, NoArgsMethod).WillByDefault(...);
//
//   // As are these:
//   ON_CALL(mock, TwoArgsMethod(_, _)).WillByDefault(...);
//   ON_CALL(mock, TwoArgsMethod).WillByDefault(...);
//
//   // Can also specify args if you want, of course:
//   ON_CALL(mock, TwoArgsMethod(_, 45)).WillByDefault(...);
//
//   // Overloads work as long as you specify parameters:
//   ON_CALL(mock, OverloadedMethod(_)).WillByDefault(...);
//   ON_CALL(mock, OverloadedMethod(_, _)).WillByDefault(...);
//
//   // Oops! Which overload did you want?
//   ON_CALL(mock, OverloadedMethod).WillByDefault(...);
//     => ERROR: call to member function 'gmock_OverloadedMethod' is ambiguous
//
// How this works: The mock class uses two overloads of the gmock_Method
// expectation setter method plus an operator() overload on the MockSpec object.
// In the matcher list form, the macro expands to:
//
//   // This statement:
//   ON_CALL(mock, TwoArgsMethod(_, 45))...
//
//   // ...expands to:
//   mock.gmock_TwoArgsMethod(_, 45)(WithoutMatchers(), nullptr)...
//   |-------------v---------------||------------v-------------|
//       invokes first overload        swallowed by operator()
//
//   // ...which is essentially:
//   mock.gmock_TwoArgsMethod(_, 45)...
//
// Whereas the form without a matcher list:
//
//   // This statement:
//   ON_CALL(mock, TwoArgsMethod)...
//
//   // ...expands to:
//   mock.gmock_TwoArgsMethod(WithoutMatchers(), nullptr)...
//   |-----------------------v--------------------------|
//                 invokes second overload
//
//   // ...which is essentially:
//   mock.gmock_TwoArgsMethod(_, _)...
//
// The WithoutMatchers() argument is used to disambiguate overloads and to
// block the caller from accidentally invoking the second overload directly. The
// second argument is an internal type derived from the method signature. The
// failure to disambiguate two overloads of this method in the ON_CALL statement
// is how we block callers from setting expectations on overloaded methods.
#define GMOCK_ON_CALL_IMPL_(mock_expr, Setter, call) \
    ((mock_expr).gmock_##call)(::testing::internal::GetWithoutMatchers(), NULL) \
        .Setter(__FILE__, __LINE__, #mock_expr, #call)

#define ON_CALL(obj, call) \
    GMOCK_ON_CALL_IMPL_(obj, InternalDefaultActionSetAt, call)

#define EXPECT_CALL(obj, call) \
    GMOCK_ON_CALL_IMPL_(obj, InternalExpectedAt, call)

#endif // GMOCK_INCLUDE_GMOCK_GMOCK_SPEC_BUILDERS_H_
